TULSA, Okla. (AP) — The woman accused of driving her car into spectators at Oklahoma State University’s homecoming parade and killing four people sped up as she approached the parade route, according to a federal report released Thursday.

The National Transportation Safety Board reported that co-workers who saw 26-year-old Adacia Chambers before the crash said she seemed distracted. The agency said her “emotional distress” was the probable cause of the crash that also injured dozens of people on Oct. 24, 2015.

This photo provided by the Stillwater Police Department on Saturday, Oct. 24, 2015 shows Adacia Chambers. Police said Chambers plowed her car into a crowd of spectators Saturday during the Oklahoma State University homecoming parade. (Stillwater Police Department via AP)

The report said Chambers’ car accelerated from 54 mph to 59 mph in the five seconds before she struck a police motorcycle blocking the roadway along the parade route. The NTSB reports that she applied the brakes after hitting the motorcycle, though the report doesn’t say how fast she was driving when she hit the crowd. The speed limit in the area was 35 mph, according to the report.

The report examined how Chambers’ emotional state may have influenced her driving performance. According to Chambers’ restaurant co-workers, when Chambers reported to work the morning of the crash, she “seemed emotionally distracted and had difficulty performing job-related tasks that she normally did well.”

When Chambers’ manager confronted her, Chambers “became emotionally distressed,” made reference to quitting her job and ran to her car, the report stated.

“Given that the crash occurred only about 10 minutes after the driver left her job, she was most likely still experiencing emotional distress when the crash occurred,” the NTSB report said.

Chambers has pleaded not guilty to four counts of second-degree murder. Prosecutors allege she intentionally drove her car around a barricade and into spectators at the parade in Stillwater. She is set for trial Jan. 10, when more than 200 victims, first responders, detectives and numerous spectators are on a list of potential witnesses.

Coleman has said his client is mentally ill and that when he told Chambers about the deaths after the crash, “her face was blank” and that he was not sure Chambers was aware that she was in jail.

Stefanie Alexander, who witnessed the Saturday homecoming parade crash, places a candle at a makeshift memorial to the victims in Stillwater, Okla., Monday, Oct. 26, 2015. A woman accused of driving her car into a crowd of people at Oklahoma State Universitys homecoming parade purposely went around a barricade, ran a red light and drove over a police motorcycle before crashing into the spectators, a prosecutor said Monday. (AP Photo/Sue Ogrocki)

Chambers’ father, Floyd Chambers, has previously said his daughter received inpatient mental health treatment several years ago but that nothing seemed amiss before the crash. He noted that his daughter had recently called and said she wanted to move back home.

A judge found Chambers competent to stand trial last December.

The NTSB said in its eight-page report that the agency doesn’t assign fault or blame for an accident, and that by regulation its investigations are “fact-finding proceedings with no formal issues and no adverse parties.”

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